Abstract: In this study, the formulation and preparation process of curcumin nanocrystalline injection were optimized to improve curcumin dissolution rate and bioavailability in vivo.Media grinding method was used to prepare curcumin nanocrystals, and the particle size was used as the evaluation index.The Box-Behnken experimental design was used to optimize its formulation and preparation process, and to characterize its physical and chemical properties.In addition, the dissolution of nanocrystal with different particle sizes was investigated by the paddle method, and the pharmacokinetics in rats were studied.The experimental results showed that the optimal formula and process were obtained through Box-Behnken experimental design, and that uniform curcumin nanocrystals with an average particle size of 223.1 nm were obtained.The results of X-ray diffraction and differential scanning calorimetry analysis showed that the crystal form was stable during the preparation of nanocrystals. In vitro dissolution experiments with different particle sizes showed that the dissolution rate and the degree of dissolution would increase if the particle size was smaller.Pharmacokinetic studies in rats showed that c_max and AUC_0-∞ of curcumin nanocrystal injection were 4.9 and 4.1 times that of curcumin raw materials, respectively.In summary, the curcumin nanocrystal injection developed in this research have a stable preparation process and can significantly improve the dissolution rate and bioavailability of the drug, which provides some ideas for the research on curcumin preparation.